NAG Library Manual, Mark 30.2
Interfaces:  FL   CL   CPP   AD 

NAG FL Interface Introduction
Example description
    Program e02cbfe

!     E02CBF Example Program Text

!     Mark 30.2 Release. NAG Copyright 2024.

!     .. Use Statements ..
      Use nag_library, Only: e02cbf, nag_wp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: xmax, xmin, y, ymax, ymin
      Integer                          :: i, ifail, j, k, l, m, m1, m2,        &
                                          mfirst, mlast, na, nwork
      Logical                          :: plot
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: a(:), ff(:), work(:), x(:)
!     .. Intrinsic Procedures ..
      Intrinsic                        :: min, real
!     .. Executable Statements ..
!     Skip heading in data file
      Read (nin,*)

      Read (nin,*) plot

      If (.Not. plot) Then
        Write (nout,*) 'E02CBF Example Program Results'
      End If

      Read (nin,*) k, l, m

      If (plot) Then
        m1 = 1
        m2 = m
        mlast = m
      Else
        m1 = (2*m+3)/7
        m2 = (6*m+3)/7 + 1
        mlast = min(5,m)
      End If

      na = (k+1)*(l+1)
      nwork = k + 1
      Allocate (x(mlast),ff(mlast),a(na),work(nwork))

      Read (nin,*) a(1:na)
      Read (nin,*) ymin, ymax, xmin, xmax

      Do j = 1, mlast
        x(j) = xmin + (xmax-xmin)*real(j-1,kind=nag_wp)/real(mlast-1,kind=     &
          nag_wp)
      End Do
      mfirst = 1

      Do i = m1, m2, m1
        y = ymin + ((ymax-ymin)*real(i-1,kind=nag_wp))/real(m-1,kind=nag_wp)

        ifail = 0
        Call e02cbf(mfirst,mlast,k,l,x,xmin,xmax,y,ymin,ymax,ff,a,na,work,     &
          nwork,ifail)

        If (plot) Then

          Do j = 1, mlast
            Write (nout,99998) y, x(j), ff(j)
          End Do

          Write (nout,*)
        Else
          Write (nout,*)
          Write (nout,99999) 'Y = ', y
          Write (nout,*)
          Write (nout,*) '  I     X(I)      Poly(X(I),Y)'

          Do j = 1, mlast
            Write (nout,99997) j, x(j), ff(j)
          End Do

        End If

      End Do

99999 Format (1X,A,E13.4)
99998 Format (1X,1P,2E13.4,1P,2E13.4)
99997 Format (1X,I3,1P,2E13.4)
    End Program e02cbfe